In machine work or assembly work, cutting oil or lubricant oil is essential. In the field of oil filling, as compared with the case where liquid type oil is used, in the case where spray that is a fog type oil agent is used, higher lubrication effect or cooling effect can be provided since the oil agent can be spread over the entire places. From such reasons, spray is widely used in the field of oil filling.
Herein, in a machining center or large lathe etc, oil agents can be filled and sprayed automatically by a specific oil filler. However, in a general purpose milling machine or a drilling machine, a disposable spray can that can be used easily and simply as is used a manual oil filler for oil filling.
This spray can generates spray as follows: a liquefied gas such as LP gas, freon gas etc. as a propellant is filled in a collected oil agent in a can to mix oil agent in the can with the liquefied gas; when a valve is opened by pushing down an actuator at the top of the spray can by finger tip, the propellant is evaporated in the can; the above mentioned mixed liquid is ejected from a pore of a nozzle by the pressure of the evaporated propellant; and when the propellant is released into atmosphere, it is rapidly evaporated and further breaks formulated concentrate particles of the oil agent into fine spraying particles, and thus spray is generated. In this spray can, using a liquefied gas as a propellant permits making the internal pressure of the can relatively low, i.e. in the range of 100 to 600 kPa (equivalent to about 1 to 6 kgf/cm.sup.2). Also the container is thin and able to be used easily and simply. However, such a spray can required 75 to 60% of liquefied gas and a container so as to spray 25 to 40% of oil agent.
Also, it is difficult for users to refill liquefied gas that is a propellant after the oil agent is used up, because excessive equipment or maintenance is required. Consequently, users have to return empty containers to the maker after use, or dispose of them. Therefore, in general, users purchase such spray cans at moderate price and manage them as consumables by disposing of them after using.
However, in particular, in a plant where machine work is conducted, since there are many places to which spray is sprayed for lubrication or cooling, a large number of spray cans are often purchased at one time. A wide variety of consumables other than spray cans are also purchased, so that inventory control becomes complicated and room for storing inventory goods is necessary. Furthermore, in the case of disposing of the spray cans, it is necessary to pierce spray cans so that the internal pressure is released to the outside. Therefore, users have to take a responsibility in such management.
In order to solve the above mentioned problems, a reusable spray can is found and provided. The reusable spray can generates spray by using air pressure by filling compressed air generated by a compressor in plant in the spray can.
This spray can will be explained with reference to figures of the spray can according to the present invention, since the basic elements of this spray can are the same as those of the present invention except a dip tube and an air hole pierced at the dip tube. As shown in FIG. 1, this spray can comprises a neck portion 11 that is removable from a spray can main body 8 at the top of the spray can. As shown in FIG. 2, the spray can is configured so that oil agent is filled in the spray can main body 8 through an opening for filling 81 at the top of the spray can main body 8 when the neck portion 11 is removed. Moreover, the neck portion 11 comprises a nozzle portion 3 in the upper part, and an air filling hole 62 in an air filling portion 6 in the lower part. From the air filling hole 62, compressed air of high pressure is filled. On the other hand, as shown in FIG. 4, a dip tube 51 is connected below the nozzle portion 3. As shown in FIG. 3, the tip of the dip tube 51 extends toward a collected oil agent 82. Moreover, unlike the present invention, in this example, the dip tube 51 whose inner diameter is the same as the external diameter of an attaching portion 41 of the dip tube is used. By filling compressed air in a state where an oil agent is collected and a can is sealed, when a valve 36 is opened, an oil agent 82 flows into the dip tube and liquid can be ejected. Therefore, the use of this spray can permits refilling compressed air from the air filling hole 62 even if the compressed air is used up, and refilling oil agent even if the oil agent 82 of spray can is used up. Thus, it is possible to reuse the same cans.
In this case, the compressed air does not liquefy at a low pressure in the range of 100 to 600 kPa (equivalent to in the range of about 1 to 6 kgf/cm.sup.2) and the expansion breaking power is inferior to in the case where the propellant is used. Therefore, as the conditions for forming an oil agent whose viscosity is about 10 mm.sup.2 /s into spray, the compressed air having the pressure of not less than 550 kPa (equivalent to about 5.5 kgf/cm.sup.2) needs to be filled since it is necessary to eject a liquid at high speed in the form of membrane and further in the form of fiber and to provide a shock for spraying.
However, the above mentioned spray can has limits in terms of the pressure of compressed air or the viscosity of oil agent, so that it cannot be adapted to all kinds of oil agent.
For example, if compressed air having high pressure of about 500 kPa (equivalent to about 5 kgf/cm.sup.2) is filled, an oil agent having a high viscosity of about 35 mm.sup.2 /s cannot be formed into spray only to flow out in the liquid state.
Moreover, since such spray cans are used in plant, it has been desired to use compressed air from tubes provided everywhere in plant as it is. However, compressed air formed by a compressor generally placed in plant is generally adjusted to about 500 kPa (equivalent to about 5 kgf/cm.sup.2). In addition, the air pressure is sometimes lowered to about 400 kPa (equivalent to about 4 kgf/cm.sup.2) because the other equipments are used. Therefore, even if the oil agent whose viscosity is 10 mm.sup.2 /s is used, sufficient air pressure cannot be obtained by using the above mentioned spray can. On the other hand, when the specific booster in plant is used, cost rises as well as the booster needs to be moved to the required places, and thus an operation becomes complicated.
Moreover, it can be said to be desirable that the use of a straw type nozzle permits operating safely since a user does not need to come closer to a work, and appropriately spraying to a small point such as a tap hole or a drill hole, and that the attachment rate is high and the scattering reduces. However, as compared with the other type of nozzle, the oil agent cannot easily be particulated by the straw type nozzle unless air pressure is increased.